The central neurochemistry service functions as a centralized laboratory for analysis of neurotransmitters and metabolites in body fluids collected within the intramural program. Routine analysis include norepinephrine in plasma urine and cerebrospinal fluid (CSF), epinephrine in plasma urine and CSF, dopamine and dopamine sulfate in urine, plasma and CSF, catecholamine metabolites, HVA, MHPG and DOPAC in CSF, plasma and urine , serotonin in platelets, platelet poor plasma and CSF and 5-HIAA in plasma, CSF and urine. GC-MS assays are used for total urinary norepinephrine, epinephrine, dopamine, VMA, MHPG, HVA, DOPAC, metanephrine and normetanephrine. HPLC with amperometric detection is used for all other assays. Implementation of microbore HPLC analysis using novel sufactant chromatographic approaches allows measurement of free catecholamines as well as serotonin in CSF. This allows examination of duirhnal rhythms and of drug effects on these amines in extracellular fluid. Some 16,000 assays were performed on over 8,000 samples which were processed during the last year.